Abstract: In a color image forming apparatus, an image retainer, a charger, a plurality of developing devices and a cleaner are made in one unit. The unit is dismountably supported in a housing so that the unit can be moved out from a first position at which the unit is set in the housing to a second position at which jam disposition is conducted. When the unit means is placed at the second position, a part of the apparatus is used to cover the image retaining surface at the transfer section.

Abstract: Disclosed is a developer comprises a toner containing colorant particles and organic fine particles, wherein said organic fine-particles are a fluoro-containing acrylate homopolymer or the copolymers thereof, each having a cross-linking structure.

Abstract: A negative charge developer for electrophotography comprises a toner and a carrier having a core coated with a resin which contains at least one magnesium compound of a magnesium oxide, a magnesium hydroxide or a magnesium carbonate, wherein the magnesium compound has a single crystal structure.

Abstract: A resin coated carrier for developing an electrostatic image is disclosed. The carrier coating layer comprises a resin copolymerized of at least three fluorinated vinyl monomers. The carrier is useful for developing a negative charged electrostatic image formed on an organic photoreceptor.

Abstract: A positive-electrification toner capable being fixed with a hot roller having a fluoro-resin covering layer is disclosed. The toner comprises mother particles containing a resin and a coloring agent, and vinyl resin fine particles fastened to the mother particles by mechanical impact force, wherein the resin has a softening point higher than that of the resin contained in the mother particles and not higher than 160.degree. C. and the vinyl resin fine particles have a frictional negative electrification quantity against iron powder not larger than 100 .mu.c/g. The toner is used for electrophotography, electrostatic printing and electroststic recording.

Abstract: The improved toner for development of a latent electrostatic image contains as a binder a polyester obtained by polycondensation reaction of a monomer composition containing the specified components and it also contains an acid-modified polypropylene. This toner exhibits satisfactory fixability, developing quality, transferability, cleanability, as well as good resistance to agglomeration and toner fusion.

Abstract: A developer for electrophotography is disclosed. The developer comprises a carrier comprising magnetic particles being coated with a fluororesin in which an alkali salt of a fatty acid is contained in an amount of from 0.05 to 0.5% by weight of said carrier, and a toner comprising a colored particle comprising a colorant and a reaction product of a styrene-acryl copolymer having carboxyl groups with a multivalent metal compound, and an inorganic particle containing an ammonium salt-modified polysiloxane. The developer is excellent in the reproducibility of fine line, the density uniformity of solid image and the fine line-reproducibility in copies formed by successive generations and the durability.

Abstract: An electrostatic latent image developer that is composed of at least three components, toner resin particles containing at least a colorant, carrier particles and fine inorganic particles is disclosed. The improved feature of the developer is that said toner resin particles contain a resin crosslinked with a divalent metal or metals of higher valency and that said fine inorganic particles are surface-treated with an ionic silicone compound.

Abstract: An electrostatic-image developing toner containing a polyester prepared by condensation polymerization of a monomer composition consisting of:Component (1): a polyvalent monomer having not less than trivalency,Component (2): an aromatic dicarboxylic acid, andComponent (3): an aliphatic dialcohol,and a releasing agent having some range of a penetration, is disclosed. The total of an acid value (AV) and a hydroxyl value (OHV) of said polyester comprises a value of not less than 30 and not more than 80.

Abstract: A method for forming an electrophotographic image, comprising forming an electrostatic latent image on a latent image carrier, developing said latent image with a developer to form a toner image, transferring said toner image on a recording material, and fixing the toner image with a heat roller, is disclosed. The method is characterized by:1) said developer comprises an inorganic fine particle having pH of not lower than 7.0, and2) a resin coating layer containing carbon black is provided on said heat roller, and is grounded.

Abstract: A developer for developing an electrostatic latent image containing (i) toner particles, (ii) inorganic fine particles of which surfaces are treated by a polysiloxane having an ammonium salt as a functional group, and a developer containing (i), (ii) above and (iii) carrier particles of which surfaces are coated by a resin, and a method of developing an electrostatic latent image by the use of the above developer are disclosed.

Abstract: A toner for developing an electrostatic latent image containing a polyester resin binder obtained by condensation polymerization of a diol component and a mixture of acid components. The acid components are an aliphatic unsaturated dicarboxylic acid or an acid anhydride thereof and a polybasic carboxylic acid having not less than three carboxylic acid groups or an acid anhydride thereof. A ratio of the polybasic carboxylic acid having not less than three carboxylic acid groups or the acid anhydride thereof to the total acid components is in the range of from 5 mol % to less than 30 mol %.

Abstract: A method of developing an electrostatic latent image wherein an electrostatic latent image with a negative polarity is formed on an organic photoreceptor and developed with a toner bearing a positive electric charge. The toner used to develop the latent image includes a binder resin, a coloring agent, silica, zinc stearate, and at least one oxide selected from hydrophobic aluminum oxide and hydrophobic titanium oxide. This method of developing the electrostatic latent image produces an image having a higher maximum image density.

Abstract: To overcome the problem of offset images in electrophotography when using a heated roller in fixing a toner image, a toner composition containing a non-linear polyester resin is used. The polyester resin is made from 1-60 mol % polyhydric alcohol having at least three hydroxy groups and 2-65 mol % of a polycarboxylic acid having at least three carboxy groups.

Abstract: Toner for developing an electrostatic latent image comprising (a) a polyester resin of a non-linear copolymer having, as its side chain, an aliphatic hydrocarbon group containing therein 3 to 22 carbon atoms, said copolymer being obtained from polymerization of an etherified bisphenol monomer, a di-carboxilic acid monomer, and a polyhydric alcohol of tri-hydric or more and/or a monomer component containing a polycarboxylic acid monomer of tricarboxylic acid or more carboxylic or more, and at least one compound selected from the group consisting of (b) an alkylene-bis-aliphatic acid amide compound represented by the general formula; ##STR1## wherein R.sub.1 and R.sub.2 are independently selected from saturated or unsaturated aliphatic hydrocarbon groups having not less than 10 carbon atoms, R.sub.3 and R.sub.4 are independently selected from a hydrogen atom and a group represented by --OCR.sub.5 wherein R.sub.

Abstract: A toner for developing electrostatic latent images which comprises a colorant and two kinds of polyester is disclosed.The fFirst polyester is a nonlinear polyester that is composed of monomers including monomers of trivalence or higher valency and which satisfies the following conditions A1 and A2, the second polyester is a nonlinear polyester that is composed of monomers including monomers of trivalence or higher valency and which satisfies the following conditions B1 and B2, and the difference between the softening points of said first and second polyesters is at least 10.degree. C.condition A1: the monomers of trivalence or higher valency represent from 0.05 mol % to less than 15 mol % of all the monomers present;condition A2: the softening point is in the range of from 120.degree. C. to 160.degree. C.;condition B1: the monomers of trivalence or higher valency represent from 0.05 mol % to less than 15 mol % of all the monomers represent;condition B2: the softening point is in the range of from 80.degree.

Abstract: Toner for developing electrostatically charged images comprising nuclear particles formed by polymerization, hydrophobic silica, and a resin, wherein said resin is coated on said nuclear particles and said silica is dispersed in said resin. A method for producing said toner is also disclosed, said method comprising polymerizing nuclear particles, dissolving a resin in a solvent, which asserts a lesser solvating action against said nuclear particles than against said resin, to form a solution, dispersing said hydrophobic silica in said solution, mixing said nuclear particles with said dispersion, and drying said mixture.

Abstract: A toner composition in particle form for electrophotography comprising an inorganic material powder, e.g., a magnetic material, which is dispersed together with other additives in a binder resin toner composed of a polymer obtained by polymerizing a polymerizable monomer, e.g., a vinyl monomer, in the presence of a titanate coupling agent.

Abstract: There is disclosed a toner for development of electrostatic image which comprises a binder resin selected from the group consisting of a polyester resin, a vinyl polymer, a styrene-butadiene copolymer, a styrene polymer, a styrene-containing copolymer and a polymer containing a reactive prepolymer; and a wax comprising a polyolefin.The toner of the present invention has excellent non-offset properties and a very low minimum fixing temperature, has high fluidity and has excellent developing and transfer properties.

Abstract: A pressure fixing method comprising passing a base carrying a toner image through a pair of rollers is disclosed. The toner contains a prepolymer and the rollers are loaded with a linear pressure of from 5 to 70 kg/cm.